Some studies of molecular ions obtained from a U + C target at > 2100°C

doi:10.1016/0168-583X(92)95922-E

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

Volume 70, Issues 1–4, 1 August 1992, Pages 142-145

https://doi.org/10.1016/0168-583X(92)95922-E Get rights and content

Abstract

The OSIRIS ISOL-facility at Studsvik is used for studies of short lived products from reactor neutron induced fission. Several species of molecular ions are produced in the target, forming sidebands to the fission mass distribution. Other species are obtained when reactive gases are introduced into the target chamber. Observations of the temperature stability of molecular ions and their formation probabilities under different conditions are reported.

References (12)

R. Kirchner et al.
Nucl. Instr. and Meth.
(1981)
P. Hoff et al.
Nucl. Instr. and Meth.
(1981)
H.L. Ravn et al.
Nucl. Instr. and Meth.
(1975)
P.L. Reeder et al.
Nucl. Instr. and Meth.
(1976)
L. Jacobsson et al.
Nucl. Instr. and Meth.
(1987)
B. Fogelberg et al.

There are more references available in the full text version of this article.

Cited by (8)

High intensity targets for ISOL, historical and practical perspectives
2008, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Citation Excerpt :
Another effect of high current operation has been the observation of diatomic molecular beams resulting from radiogenic production of both constituents. The formation of MeF+ ions from injection of CF4 into targets is a well know technique for enhancing release and mass separating isobars [44–47]. However, with sufficiently high production under intense irradiation it is possible that both radiogenic metal and halogen atoms can form such species without any intended addition of reactant gas.
The concepts and technical challenges of generating radioactive ion beams from ISOL (isotope separation on line) targets irradiated with high power proton beams are discussed in an historical context. The evolution of potential target designs for high beam power dissipation over the past 20 years is reviewed with respect to effectiveness and practicality. The development of TRIUMF-ISAC high power targets and their successes and problems during on-line operation at elevated proton currents are presented.
In-pile arrangements of reactor-based RIB facilities
1997, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Two Radioactive Ion Beam facilities are projected at high-flux reactors: PIAFE at the Institut Laue Langevin in Grenoble and the Munich Fission Fragment Accelerator at the FRM-II in Garching. Both will operate with a “nuclear heated” target-ion-source assembly (fission rate ≈ 10¹⁴ S⁻¹) in an in-pile position in a neutron flux of the order 10¹⁴ cm⁻² s⁻¹. The expected beam intensities are several orders of magnitude higher than those of existing ISOL facilities which use thermal neutron-induced fission. The major difference between the in-pile parts of the projects is the type of beam tube: PIAFE will use a single-ended tube where target change and ion extraction are done to the same side — at the FRM-II a tube with access from both sides will be used, allowing a spatial decoupling of target handling and ion extraction. Different methods to master the new technical challenges arising from the high neutron flux are discussed.
Release studies of elementary and metal-fluoride ions at the GSI on-line mass separator
1997, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
By using the techniques of implantation of heavy ions and of bunched-beam release at the GSI on-line mass separator, systematic release studies were performed. With the first technique the complete release process from the catcher-ionsource-system is analyzed in detail for 31 new tracer-host combinations. These include as new tracers the elements Ti, V, Zn, Sb, and Dy, and carbon foils of around 1 mg/cm² thickness as new catcher matrix. The carbon foils allow for a more reliable determination of rracer diffusion properties in carbon, avoiding the problems with porous sinter-graphites, where closed pores, inconsistencies in the manufacturer's data on grain size, or grain growth cause unacceptably large discrepancies within the derived diffusion coefficients. Measured with the bunched-beam-release technique, the mean adsorption times of the fluorides of group IIA and IIIA metals turned out to be orders of magnitude shorter than for the respective atoms, thus showing quantitatively the benefits of the CF₄-fluorination technique. The degree to which the respective alkali-fluoride ions are suppressed was determined to be < 10⁻⁵, compatible with zero. The degree of fluorination is high in most cases, even for very low CF₄ partial pressures.
Efficiency and delay of the integrated target-ion source of OSIRIS
1992, Nuclear Inst. and Methods in Physics Research, B
The new compact target and ion source system of the OSIRIS ISOL-facility at Studsvik has now been in use for about five years. The system is used for studies of short lived nuclei obtained through fission with reactor neutrons. The ion source can simply be switched between two modes of operation, one being (thermal) surface ionization and the other an electron impact induced plasma mode. The efficiency for most elements in the fission product region has been measured. The use of a substantial (gram quantity) amount of target material introduces a delay between a fission event and the subsequent ionization of the products. This delay in a U+C target has been analyzed for several elements. Some observations of nuclidic yields as a function of the target temperature are reported.
ISAC targets
2014, ISAC and ARIEL: The TRIUMF Radioactive Beam Facilities and the Scientific Program
ISAC targets
2014, Hyperfine Interactions

View all citing articles on Scopus

View full text

Some studies of molecular ions obtained from a U + C target at > 2100°C

Abstract

Nucl. Instr. and Meth.

Nucl. Instr. and Meth.

Nucl. Instr. and Meth.

Nucl. Instr. and Meth.

Nucl. Instr. and Meth.